Red-Shift

• Red-shift


  An observed increase in the wavelength of light from distant galaxies
• The further away a galaxy is

  The faster it is moving
• The further away a galaxy is

  The greater the observed increase in wavelength
• Red-shift


  • Provides evidence that the universe is expanding
  • Supports the Big Bang theory
• Big Bang theory


  The entire universe started from a very small, hot and dense region in space
• The galaxy that is further away

  • Is travelling faster
  • The observed red-shift is greater
• Scientists observed supernovae, which suggested that galaxies are moving away at an ever faster rate
• Prior to observations of supernovae

  The rate of expansion was expected to occur at an ever slower rate due to gravitational forces
• The existence of energy and mass that we can't detect, known as dark matter and dark energy, could explain the universe's ever increasing rate of expansion
• These ideas about dark matter and dark energy are still being developed by scientists and are not yet fully understood